This spectacle is a sure-fire crowd pleaser, with giant fires, plenty of steam, and dangerously hot boiling liquids. And because of the intense caramelization of the wort by the hot rocks, the beer’s a delight as well.
My friend, Ray Spangler, used to organize a stone beer demo at the infamous Oldenburg Beer Camp. He employed palm-size granite stream cobbles. These are generally stable and not prone to flaking, as are rougher rocks.
For a 5-gallon batch, you’ll need about 7 to 8 pounds of rocks, weighing about one-half to 1 pound each. The original stone used in Bamberg, Germany, is called greywacke and is somewhat hard to find. The best candidates are dense, igneous (volcanic) rocks, such as granite or basalt, and I’ve heard that quartzite works as well. Avoid limestone or other sedimentary rock, as it is porous, soluble in beer, and prone to cracking.
Be aware that any rock can shatter violently when heated, especially when the heating is rapid. Be sure that everyone brewing is wearing goggles or safety glasses. There’s bound to be some splashing, too, so suit up.
This is a good cold weather extravaganza. You’ll need a roaring campfire. Place the stones in the fire, and heat them until they’re as hot as you can get them—glowing red or white. Use long tongs to transfer the stones into a basket made from stainless steel strapping or screen mesh, with brass or stainless chains attached from the basket to a wooden pole that two people can handle. Then, slowly lower the rocks into the brew.
There will be a dramatic release of steam; people will ooh and aah. Once the steaming has subsided, pull out the basket of rocks. The heat of the rocks will further caramelize the wort on their surfaces. When the wort gets nice and dark, you can add it back to the kettle. Complete the boil with a conventional heat source.
The Germans put the caramelized rocks in the fermenter, but with smaller rocks, it’s not necessary. Stone beer is a fun but complicated brew, and is worthy of further study before attempting. Check out back issues of Zymurgy and Internet newsgroups such as Homebrew Digest. And do be careful!
A Group Brew
Just getting everybody’s equipment together for a brew can be a lot of fun, whatever the beer. While this usually takes place in backyards and driveways, it can be much more extreme. For example, the Bloatarian Brewing League has a campout—Beer & Propane—that culminates in a mystic late-night campfire ceremony, complete with holy relics, silly hats, and the pounding of the symbol of Evil Order (as represented by a can of mega-brew) into the earth.
One of my brewing buddies makes a beer at the start of a week of river rafting, to be consumed at the end of the event. It’s a little rough sometimes, I guess, but there are never any leftovers.
All you need for such festivities is fresh water, a non-flammable surface, and an understanding (or homebrew-loving) life partner. I’m hosting such a brew-in for my club on National Homebrew Day, May 5. The attractions will include barbecue and an equipment swap meet as well as profligate brewing.
The American Homebrewing Association organizes a communal event called Big Brew in celebration of National Homebrew Day. If you are so inclined, I urge you to check it out on their aforementioned website. Whatever you do, just get together. It’ll be a blast.
I hope to hear the roar of propane all over this great nation that day.